<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta http-equiv="X-UA-Compatible" content="IE=edge">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
</head>
<body>
  <div id="app">
    <com-a>
      <!-- <template #header> -->
        <template v-slot="header">
        <h1>组件的标签内容</h1>
      </template>
      123
    </com-a>
  </div>
</body>
<script src="./lib/vue.js"></script>
<script>
  // 子组件
  Vue.component('ComA', {
    template: `
    <div>
      <header>
       <slot name='header'></slot> 
      </header>
      <main>
        <slot></slot> 
      </main>
      <footer>
        <slot name='header'></slot>  
      </footer>
    </div>`
  })


  new Vue({
    el: '#app',
    data: {

    }
  })
</script>
</html>